• Journal of Advanced Marine Engineering and Technology
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• v.38 no.1
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• pp.15-22
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• 2014

Multiple devices have been installed to reduce exhaust emissions and to increase thermal efficiency. Those devices reduce the exhaust pipe opening area and increase the exhaust gas pressure. The pressure increase disturbs a gas flow and has a bad effect on the engine performance. However there is some study that NOx can be reduced with exhaust gas pressure increase. In this study an engine performance is tested with various opening ratios. The result shows that the fuel consumption rate is reduced in case of little amount of the pressure increase, and NOx is reduced with the pressure increase, while the concentration of the toxic exhaust gases are increased in the case of high back-pressure.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.99-104
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• 2008

Gas pressure regulators in pressure regulating station reduce high-pressure gas in a process line to a lower. Gas pressure regulators are not flow control devices, they are used to control delivery pressure only. For the safety of pressure regulating station, it is essential to study flow regime and characteristics of a safety valves that is connected to a pressure regulator. For this, it is necessary to understand flow characteristics and the flow rate of upstream component part such as gas pressure regulators in regulating station. In the present study, numerical analysis of flow characteristics and the mass flow rate of a pressure regulator is conducted under the several inlet, outlet conditions and open rates. Then, the numerical result of the mass flow rate is verified with experimental equation from manufacture of pressure regulator. Consequently, the numerical result is comparatively good agreement with values from experimental equation.